Prognosis associated with asymptomatic intracranial hemorrhage after acute ischemic stroke: a systematic review and meta-analysis

Background and purpose It remains inconclusive whether asymptomatic intracranial hemorrhage (aICH) after acute ischemic stroke is innocuous. We aimed to conduct a meta-analysis assessing the relationship between the aICH and poor neurological outcomes. Methods We searched PubMed, EMBASE and Web of Science from their inception to 30 November 2021 and performed a meta-analysis on the association between the aICH and neurological prognosis after acute ischemic stroke at 3 months, including poor outcomes (modified Rankin Scale [mRS] score >= 2 or mRS >= 3) and mortality. Results Fourteen studies were included in the analysis, reporting on a total of 10,915 participants after acute ischemic stroke. The risks of poor outcome (mRS >= 2 or mRS >= 3) in patients with aICH were significantly higher than patients without ICH (OR 1.70, 95% CI 1.33-2.18; OR 1.43, 95% CI 1.20-1.70, respectively), based on adjusted data. The difference between the two groups was not significant for mortality. The results of subgroup analysis showed aICH were associated with higher ratio of mild poor prognosis (mRS >= 2) (OR 1.59, 95% CI 1.11-2.27), but it had no association with functional dependence (mRS >= 3) after recanalization. No significant influence of aICH on poor outcome (mRS >= 3) was found in non-recanalization group. Further stratified analysis revealed that only aICH with patients receiving endovascular therapy (EVT) could increase the risk of mild poor prognosis (mRS >= 2) at 3 months. Conclusions Our results indicate that compared with patients without ICH, those who developed aICH during the acute stage of ischemic stroke had an increasing risk of worse outcome, especially in patients with endovascular therapy.